Telephone-exchange system



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1927' ca. A. E. LUNDELL TELEPHONE EXCHANGE SYSTEM Original Filed April 11, 1921 3 sheets-sheet i M: w YEN c C l c D avwemtoz Patented Aug. 9, 1927.

GEORGE ALBEN E. LUNDELL, or ivnw-YonK, N. Y. I

TELEPHONE-EXCHANGE SYSTEM.

Application filed April 11, 1921, ,Serial No. 460,271. Renewed January 8, 1927.

of movement of a rotaryswitch adapted during such movement to send impulses of current.

. Another object relates to the selection of coin box operating currents of varying character and selective signalling currents of varying character, by means of a single selecting instrumentality.

Other objects willfappear as the descrip- V tion of the'invention progresses.

The present embodlment 1s one of a variety of forms in which the invention may v be practiced, and it is understood that the scope of the invention is not to be determined by such disclosure, reference being had to the appended claims for thatpurpose.

Referring to the drawings,

Figure 1 shows a pair of calling lines, and diagrammatically a link circuit for extending a telephonicconnection;

Figure 2 shows the outgoing end of a trunk to an operator; and'should be placed to the right of Figure 1;

Figure 3 shows the incoming end thereof,

and a cord circuit with a rotary switch, and

should be placed below Figure 2.

.Referring to the drawings, upon making a call from station 601 for station 274, a coin 602 is placed in the coin'boz; 603, and the receiver is removed from its hook. Station 601 is joined tothe central office by means of a pair of conductors 604, 605, and is provided at the central oflice end thereof with a usual line and cutoff relay. The connection may. be extended in any well known manner to operators trunk circuit 248, 249, 266. The link circuit interconnecting said line and said trunk circuit may consist of finder 29 and selector 30 such as shown and described in my co-pending application SerialNumber 457,757 filed April 1, 1921, or

any other suitable mechanism. The regis te r sender shown within the dash dotline of F1 gure 1, after causing-the establishment of such connectionrestores to normal and also causes the sequence switch of power magnet 49 to, move to posltlon 14.

Thesequen'ce switches shown 1n various parts of the drawings comprise sets of contacts such as 620 adapted to close contacts in the various positions of the sequence switch. The numerals which. appear adjacent thereto indicate the positions of the sequence switch at which such contacts are closed; with the exception that the center-. ing spring, shown immediately above the power magnet is open only at the positions indicated by the numerals adjacent to it and therefor the sequence switch canstop only in these positions; Motor mechanism is provided for rotating the sequence switch through its successive positions. This mechanism is employed during the energization of the power ma'gnet for driving the sequence switch.

When a call is originated by a subscriber the sequence switch 49 is moved out of position 1 by the operation of suitable line and control relays (not shown) in a manner well knownin the art. The wipers 57, 58 and59 are advanced over sets ofterminals with which they co-operate andare stopped in contact with the terminals of a calling line. A busy'testcondition is placedupon the test conductor of a line byway ofsequence switch contact resistance coil 69 to a source of test potential 68. Connection is also established for the purpose of registra tion to a register sender over conductors 70, 71 by way of sequence switch .contacts 73,

76 to control relay72 whereby the register I '95 ner under control of the calling device at i sender may be adjusted in well known manthe calling subscribers station in accordance with the. wanted subscrlberls'llne number. The sequence switch 49 1s advanced to p'os1- tion 10. The wipers 116, 117, 118 of the sev lector switch 30 are advanced over sets of terminals with which they co-operate and into contact with a set of terminals in'a desired group in well known manner and in accordance with the adjustment of the regis- 49, sequence switch contact 243, conductor 1 tion 13 into position 14.

closed from ground, sequence switch contact transformer 26? to ground. closed from ground, left-hand armature and front contact of relay 103, sequence switch T contact 47,-winding ofpower magnet 49, to

242, front contact and armature of relay 203 to ground. The sequence switch'49is ad vanced out of position and through posi- A circuit Is now 126, left-hand winding of relay 103 to grounded battery 104 therebyoperating relay 103. A circuit is now closed from grounded battery, winding of repeating .coil 246, 'Fig. 2, winding of relay 607, right-hand back contact and armature of 606, conductor 249, wiper 117,1fi 1, sequence switch contact 73, wiper 58, conductor 605, subscribers station 601, conductor 604, wiper 59, sequence switch contact 76, conductor 163, wiper 118, conductor 248, left-hand back contact and armature of relay 606, Fig. 2, winding of re peating coil 246 toground, thereby operating relay 607. A circuit is now closed from .grounded battery 262,. 3, winding of relay 252, armature and back contact of re lay 253, conductor 254, winding of repeating coil 246, Fig. 2, front contact and armagrounded battery for, moving the sequence ,switch 49 out of position 14 and into posi- 7 tion 15.

Reference characters below 400 refer to likeparts in the application cited above.

7 Thecircuit above. described for operating relay 219 included also the winding of relay 252,-andthis relay; operated thereby closesthe local circuit including the lamp 265 and Y causes the illumination of the lamp.

Vilhile passing through position 14, sequence switch contacts 73, 76 momentarlly connect relays 172, and 607 in parallel, but

this condition is only temporary and vpro- ;duces nofeifect upon the operation of the system.

The lighting oflamp 265 attracts the attention. of an operator She inserts plug winding of relay 253.

268intov jack 239 closing a circuit for the The operation of relay 253 cuts off relay 252, the consequent release of which etinguishes lamp 265. The operator actuates listening key 271 to place herself in telephonic communication with station. 601. V v V r'hCllCtllt is also closed from grounded battery 269, windings of repeating coil 273 and s'ignali270, contactof key 609, plug 268, jack 239, conductor 254, winding of repeating coil erating relay 259 and signal 270. Relays 259 and 610 are polarized relays, and the cur= rent now flowing through their windings operates relay 259'but not 610. Relay 259 closes a circuit from grounded battery,winding of relay 264 armature and front contact of relay 259, right hand winding of relay 263 to ground, operating relay 264 and 263. relay 264 breaks the circuit of slow release relay 219 which releases, but relay 264 maintains the connection of conductor 266 to ground.

The operator-establishes a desired connection to station 274' in any suitable manner, employing well known 7 connecting means such as cords, plugs a'ndjacks.

The operator ascertains theclass ofservice of the calling line by listening for the class of service signal tone on the test conductor of his line. This she does by actuating key 609 (leaving key 271 also operated). A circuit is closed from grounded battery, windings of repeating coil 273 and signal 270, uppermost contact of key 609, sequence switch contact 611, leftv hand back contact, and ari mature of relay 612, contact 61301" key 609, plug 268, jack 239, conductor 261, left hand armature and back contact of lrelay 614, windings of repeating coil 246 and relays 610, 259, contact of relay 607, winding of repeating coil 246, conductor 254, jack 239, plug 268, contact 615 of key 609, winding of repeating coil'273 to ground. It will be noted that current through windings of relays 610 and 259 is reversed, consequently relay 259 releases and relay 610 operates. A circuit is closed from ground,armature and front contact of relay 610, winding of slow release relay 614 to grounded battery, operating relay 614. The operation of this relay opens a short circuit around the winding of relay 616, but relay 616 is marginal and will not operate on low voltage battery 269. Relay 614 closes, at its eXtremeright hand front contact, a circuit for maintaining operated relay 264, independent of relay 259. A circuit is closed from ground, lowermost contact of key 609, sequence switch contact 617, winding of relay 618 to groundedbattery, operating relay 618. A circuit is closed from ground, armature 619 and front contact of relay 618, sequence switch contact 620, winding of power magnet 621 to grounded battery, for moving the sequence switch of Figure 3 to position 2.

The operator now actuates master key 623, closing a circuitfrom ground. armature 619 and front cont-act of relay 618, key 623, sequence switch contact 624,- winding of power magnet 621 to grounded battery, for moving the sequence switch out of-position and under control of its centering spring 622 into position 4. In position 3, the circuit ofrelay 610 is momentarily broken once at sequence switch contact 611. Thisreleases relay 610 momentarily, and closes once a circuit from ground,-armature and back contact of relay 610, armature 625 and front contact of slowrelease relay 614, winding of magnet 626 to grounded battery.

, Magnet 626 forms part of a step by'step selector switch 627, comprising also a ratchet wheel 628, wiper arms 629, 630, 631, 632, each ofwhich is provided with a row of contacts, with which they contact in sequential order, and after being stepped away from the last contacts of their rows, theyare brought into engagement again with the first or normal contacts. I

Said wiper arms aremoved from their first totheir second contacts by the single operation of magnet 626 described 'A circuit is closed from ground, upper contact of key 623, sequence switch contact 617 for maintaining relay 618 energizedindependent of key 609. Although the original energizing circuit of this relay is opened by the lower sequence contact 617, this relay is locked through its right hand front contact independently thereof. A circuit is closed from ground, armature 619 and front contact of relay 618, key 623, sequence switch contact 633 (this sequence. switch is in its 609, winding of repeating coil 273 to ground, operating relay 616 and retaining relay 610 operated.

A circuit is closed from ground, armature and front contact of relay 616, arm632 on its second contact, winding of relay 636 to grounded battery, for operating relay 636.

Thus the secondary winding of the induc-' tion coil267 is connected to conductors 254,

V 261 and the operator may overhear the class of service tone. The inductive connection 7 includes condensers 637, 638 and 639.

operator advises the calling party how much additional money is to be deposited by him,

itany. Asthe coins drop into thebomthey produce distinctive audible signals, ina well ground at station 601.

' of said relays.

known manner. Shethen operates key 640 and thus'close a circuitfor the power magnet 621, 111' a manner similar to that" de scribed above, for moving the sequence switch'into position. 8. During this movement, sequence switch contact 611 twice breaks the circuit of relay 610 momentarily, again actuating magnet 626twice and moving wiper arms 629, 630, 631, 632 two steps,

to their fourth contacts. In position 8, relay 612 is again operated, and causes the operation of relay 616 as before. A circuit is thereby closed from ground, armature and, front contact of relay 616, arm 632, winding ofrelay 606 to grounded battery, operating relay 606.

v A circuit is'fclosed from grounded high voltage source 641, w nding of relay 642,"arm 629, left hand'fron't contact and armature of relay 606,00nductor 248, wiper 118, conductor 163,. sequence switch contact 6, wiper'59, conductor604,

winding and contact of coin boX 603 to polarity ofsou'rce 641 are such as-to operate the magnet of the coin box 603' in a direce tion to deposit the money. Relay 642 operates and inductively connects an inter; rupter 644 to the repeating coil 246, producing a tone in the operators receiver 272 as a check on the operation of the coin box. Release of key 640- deenergizes relays. 612, 616,606and642.

The operator may now restorexkey 609 to normal. Relays 618,610, 614 are released and. relay 2559 again operates. oi relay 618 closes a circuit 'from' ground,

armature 619 a'ndback contact of this relay,

The release The voltage and 7 sequence switch contact. 620, power magnet 621 to groundedbattery for restoringthe sequence switch to-its normal position. Release of slow release relay 614' closes a circuit from ground, armature and'back'contact of relay 610, armature 625 and back contact of relay 614, arm 631, winding of relay 664 to grounded battery. Relay 664 operates and locksto arm 631 independently A circuit is closed from ground, left ha-nd armature and front con tact of relay 664, arm 631 on anyof its'off i normal contacts, right hand contact of relay 664, back contact and winding of magnet 626 to grounded battery. Thus magnet 626 is intermittently operated until switch 627 is i'ully restored. Relay 664 then releases,

its ci'rcuit'being controlled by arm 631.

I Upon completion. of conversation, signal 270 releases when relay 607 releases, as it is adjusted not to remain operated in. series with the'high resistance winding of relay 263, and the operator pulls down plug268. I This deenergizes and releases relays'253, 259,

264, 263, 103., Relay 103 causes the restora-. tion to normal of the link circuit of Figure 1 in the manner described in the above mew tioned application. v

Had she so desired, the operator might have returned the coin 602 to the calling party. She would then have used key 645. The sequence switch of Figure 3 would have been advanced only to position 6 and switch 627v to its third contacts. Thus source 646 would have been made active instead of source 641. The polarity of source 646 is suchas to cause the magnet of coin box 603 to eject the money. The. operation of relay 647 connects a difl'erent interrupter 648 to to talking set 272.

Ringing back.

Assuming acall from station 650 for sta tion 274, the operation is similar to that already described up to the point where the class of service indication is obtained. Sta- .tion 650 being a party line station, there is connected to the test conductor 653 of its line-a differently characterized source 654 of tone current. This the operator recognizes as being that of a four party line, it being assumed that there are four stations connected to line-conductors, 651, 652.

The sequence switch of Figure 1 is at this time in position 15, that of Figure 3 in position 4, and switch 627 on its second'contacts. If the operator anticipates a delay in completing the connection to wanted station 27 4, she mayask the calling party to replace his receiver on its hook until she signals him.

VVhen he does so relay 607 releases, opening a short circuit around the left hand windings of relays263 and610. The windings of'relay 263 are connected so as to be at this time mutually aiding. Let it be assumed thatmeanwhile theoperator has, other use for master keys 62 3, 645, 640, 655, etc., say

in connection; with another cord circuit. She releases key 609. This releases relays 618, 610, 614 and restores switch 627 to normal as before. The sequence switch of Figure 3is also restored to normal.

Upon desiring to signal station 650- the operator actuates key 609 and also 655 the 7 selection of which depends upon the desig- V nating number previously given by the calling party. I r

The actuation of key 609 operate-s relay 618 and causes the sequence switch of Fig ure3. to move to position 2 as before; re-' p energizechland upon their operation a signalling circuit is closed'as follows: the negative brush of a current source 658 producing ne tive pulsating current, arm 629, left hand frontfcontact and armature of relay 606, conductor 248, wiper 118, conductor 163, sequence switch contact 76, wiper-59,

conductor. 651, selective signalling apparatus ofstations 650 and 660 toground thereatl The signalling apparatus of station 660, is

,iack 239 and thus releases relays 253, 259,

264, .263, 103, and the apparatus fully restores as previously described. l Vhat is claimed is: i V 1. In a telephone exchange systennthe combination with a line having a coin box adapted to operate on either of two polarities of direct current and a selectively signalled party line of a single rotatable, selector.

switch adapted to select a desired polarity of coin box curren'tor a desired selective party line actuating current. v i

2. In a telephone exchange system, the combination with a plurality of selectively signalled stations, asinglefpair of conductors for said stations, a source of characterized current for selectively actuating a de sired one of, said stations, arotary switch having a plurality of stopping positions, a contact on said switch opened once between each two of said positions and a plurality of keys adapted to render transitional a predetermined number'of said positions of a selector controlled by said contact and adapted to selectively actuate said source for signalling said station. V

3. In a'telephone exchange system, a polystation line having a plurality of selectively signalled stations, a second lin'e having a coin box, polarized magnet for said coin box operating in one direction to deposit coins and in the opposite direction to eject coins,

a source'of' signalling current for each of said stations, 2 source of uni-directional current of one polarity for operating said magnet in one direction, a second source of unidirectional current ,of opposite polarity for operating said'magnet in the opposite direction and a single selecting means for selecting any one of said sources. V

4. In a. telephone exchange system, the combination with a line having a coin box adapted to operate on either of two polarities of direct current and aselectively' signalled party line of a single selector switch means adapted to select a desired polarity of coin box'current or a desired selective party line actuating current. p

5. In a telephone exchange system, a polystation line having a plurality of relatively differently responsive stations, a single station line having, a selectively operable elec tromagnetic device, a plurality of sources of power for signalling said stations and for actuating said device, and a single selector for selecting any one of said sources.

6. In a telephone exchange system, a selectiye party line, a direct line having a polarized device, a pluralityfof variously characterized sources-of current adapted t0'.1 signal a party of the line, a plurality of vahand this 9th day of April, 1921:

GEORGE ALBENV E. LUNDELL.

y In testimony whereof, I hereunto set my I 

